I used one of those flower rug thingys years ago. It worked quite well. It certainly is far easier than the old fashioned, digging in the dirt way. ;*)
I hear you. I would really like to avoid anything that would mess up my purple nail polish. I've been thinking of getting a cute pair of Wellies to wear while I water my little patch of garden 'rug.' I'm pretty sure that looking cute while you work is half the battle. : )