Hey Squash,

You can use a basin, I like to put it on in the bathtub after I use my bathmate. You shouldn't need to wrap. Unlike air which is compressible, water acts more like a solid and should protect the glans. Here is a step by step guide posted by capernicus1. Try it out and let me know how it goes.

When using water you only need a very short length of sleeve, mines about 2” so there’s only about an inch of sleeve covering the shaft.Here’s how I do it.
Roll the sleeve onto the hanger
Attach the vac tube
Fill a hand basin or bowl with warm water
Put the vac tube in your mouth
Put the hanger in and then push you head in while keeping the whole thing under water
Unroll the sleeve under water
hold the hanger upright and suck out any air bubbles , then suck out as much water as needed ( you don’t need much, pull on the hanger to get a feel for it )
Seal the vac tube and you’re done.
Takes a bit of practice but it’s really easy.