I don't understand your hesitation Migrant, or your disaster Randy. BaaBaa is correct, you have to do it while sitting and Mags is correct with the rear approach.
I admit I did have a few aiming adjustment problems the first couple of times I used it but it was a very short learning curve. I did install the better ones in my house, not the cheapest plastic ones with the rubber hose that you see here in a lot of places, so mine have a very concentrated spray and with the twin Mitsu 305s powering the water from my two in ground tanks, I can get very, very, clean after even the most disgusting movement!
I will never be able to live in the west again without installing one of these things in my "loo", just can't get that clean feel without it now that I'm used to them.
It's kind of like flossing your teeth in that respect. When I was young, I didn't bother as I thought it was too much trouble. Then a dentist talked me into trying it for a month and now I can't imagine going a day without flossing... just wouldn't feel clean. Maybe you guys that don't like the water gun could invent some butt floss...
