I use one of the compression type ones (floor/battery to ceiling). Has two vertical poles and then three sliding ovals horizontally. Cost about $60-70cdn at most dept stores.

I was worried about the battery but as long as you don't over do it, i.e., extend it just enough to keep it up without wiggling it should be fine....mine's caused no issues. There is nothing anywhere that I can find warning about carrying too much weight, sharp objects, etc. etc. (any different from non-feh).