Commercially made stuffers/boosters are made to let liquid flow into and through to the primary outer diaper. Boosters substancially increase the capacity of your diaper. There are numerous boosters available to the diaper wearer.
At times I use a real "prefolded cloth baby diaper, such as a Birdseye or Gerber directly next to my skin under my diaper as the first layer of my disposable adult brief. IMHO, this gives a similar feel as wearing a real baby disper.
The minimum modification of an adult diaper or other protective undergarment is to create slits in the outer covering/layer of the diaper to serve as the booster. A sharp knife such as an exacto knife is up to the task, but I use sharp utility scissors (Clauss ExtremeEdge Titanium) to cut small v slits about every 2" over the surface. You may also want to cut off all non-absorbant material around the diaper Llaving an hourglass shaped booster. If you want to increase capacity at the front of the diaper cut the booster at the middle to create two boosters to stack.
My nighttime diaper consists of my outer diaper, an hourglass shaped modified booster and two 1/2 boosters. Don't have to change till morning. As I wear 24/7, I have 2-3 changes per day. I use average of 4 diapers per change, so 8 - 12 diapers per day. Cost runs .15-.25 per diaper, so .60 - $1.00 per change/$3.00 day
This is an example of my typical night-time diaper:
A Prevail Protective Underwear with cut slits, 2 Dignity Double Duty Booster Pads, a Tranquility Top Liner Booster, a Tena Classic Plus Brief cut into hourglass shape as a full booster, a Euro Brief Adult Diaper, all under four cotton whitey-tighty briefs, and a pair of Salk Sani-pants.
This gives me a capacity of up to 128 ounces. Despite this, I often-times do have to change during the night.