We have slightly modified the application, my husband laid the strips dry on my stomach and then painted with a paintbrush on the water. We thought that was much easier and more accurate than soaking the strips in water and then place it on the belly. And it also works very well in this way. Upon drying, we hurried along with a hair dryer, which also worked great and fairly speeds up the process.
In my opinion, the plaster cast while standing is at its best, because you can capture the belly rounding best. But that's really seeeeeeehr exhausting !!! After an hour, I could no longer stand properly and I was always slightly dizzy. When drying my circulation has then abandoned, I almost passed out - we were able to settle the plaster cast just in time and without damage.
So make the best of a "good" day, otherwise it can go wrong!