Any technique will be a whole lot easier in a 4 yard kilt. An 8 yard kilt has a lot more fabric and weight to contend with.
I've heard of guys loosening the kilt and pulling it up under the armpits, taking it off, flipping up the pleats, putting the aprons at the back and flipping up that instead of the pleats.
I think velcro closures would be somewhat loud in a public bathroom.