I do get the want/need to be able to feel the punishment for quite some time as a good reminder. I for one though have myself remembered and had other things be a much better detterant and/or reminder after the fact.
My #1 is goin to bed without dinner being hungry, you think about it all night for sure, and if you in a position where the SO is in charge and your able to get food yourself at that point then the situation is entirely in thier control as to how long it will be your hungry, and for most people there is not much chance of any long term issues at all to your health (of course medical conditions specific here, check with your dr if you unsure)
#2 is something taken away. Like no web surfing/youtube/etc, no phone, no computer, etc. You left with little of your usual things to do and likely will think about the reason your without these fun safety blankets we have these days and are usually addicted to. This can be however long your CG/SO/etc want it to be. I know my devices are and have been for a long time under the apple screentime and my PCA has the code for screentime and the ability to adjust as needed, and my SO did as well, but no SO at the moment, but my account is also setup as young age for b-date so, really not a way i know of around it, as i also dont own the business account it is under either, but if i really needed i could ask the main account holder to change the screentime password, but that owner is my actual mom, and not easy to do that for many reasons.
#3 if in a sexual relationship, there is always chastity devices that are available. They will remind you constantly of the reason your in one and what you did to get there. Not something your going to forget about by any means and very frustrating to say the least.
And others.
From an AB sense,I'd say that setting up parental controls on your devices would be a good option, give the CG/SO the ability at any time to restrict your activities, and if you do something wrong and/or break a rule the punishment will be know as soon as you try to watch youtube or get onto a website. Your CG/SO will also be able to adjust as needed for whatever the infraction is.
I know both AB's and non AB's that use this parental restrictions for many reasons, from wanting to stop watching porn, to actual use for keeping things off for sleeping.
I used/use it for setting times when i need to sleep (right now that is not going for some reasons outside of me), the PCA will set the times when the ipad/phone is off and then there is only calling enabled to them and a couple of emergency contacts available, and beiing my devices are setup on account that is underage, there is no way to bypass the screentime systems, even formattingthe device, screentime will reenable the min it contacts the internet again. If your account is over 18yo then there is ways to bypass things pretty easy. You need to be on an account with multiple phones, and the owner needs to be someone else, and your account b-date need you to be under 18, then the main account can setup the screentime and your locked into it, and there isnt from my knowledge any way around it, i doubt if i even called apple they'd do anything, as my phone is not the account holder and is for somone under 18, id need the main account holder information to change anything, and the PCA's can use any ipad in the house (have many) to adjust the times, and/or anything else on the screentime as they do have the code to screentime and i do not, they actually setup the code with my mom for this, and was open with the use of it for turing things off when supposed to be sleeping, so they can adjust it when needed, as sometimes i need to be sleeping at different times and alike, and they have also used to enforce certain rules/things like eating right, or even just being nice, as when im not feeling good i do get cranky often, and they dont need to deal with that. So, they are allowed to do that, Like if i was not nice/courteous they have right away put me to bed and then turned off the devices, which is not that fun...
But, i know (one ex loved to be spanked) people also like getting spanked for the pain and feeling, which is totally fine, but i also dont think at adult age too many are really looking at a spanking as a serious punishment, it's not like getting caned from the court like in other countries, that looks not too fun. and to get an adult to the point of if being a punishment IMHO would get into the point of making perm marks and/or open wounds being inflicted and that comes with some possible serious issues especially if your in diapers, you might easily get infection setting in and that isnt very good.
IMHO if your looking for a punishment, there are ways to do it and it being remembered for a long time and/or being it lasts a long time without the use of physical force at all, and little if any long term issues.
I think that most people here would be very obidient if there is someone else incharge over thier devices to use the internet.
Would you break a rule knowing that you'd lose your internet providleges for "Real" at your CG/SO's whim.
ex. Clean room/Do dishes every day. If not lose your internet for a week. Knowing fair well that you will really lose it and would take a lot of hassel and/or even being able to restore it without thier permission.
Simply takes you both being on same phone account and they being the account holder only. and setup your account with a b-day like 14yo or so, setup parental controls. Gives them full control over the device without any asking you or you needing to let them do it, they simply change the settings then its off.
I think that would be a better punishment and/or threat to keep you doing whatever than a spanking would do. even if you are spanked to the point of tears and not sitting down, that wont last even a day or so, where this will last as long as the CG/SO want it to, wether you like it or not it's thier decision alone.