Never use the scrubby side, just use the sponge. Soak the bucket, carboy, or BB in water to soften the krausen that's stuck high on the walls of the fermentor. Everything comes off with a simple wipe.
The plastic buckets and BB will still smell like hops/beer. I've tried everything but nothing really gets the white walls of the fermentation buckets completely white again, i.e., they remain yellowish.
Regarding spigot placement--two things:
1.) I recommend that you check your spigot first--you don't want your spigot extending below the bottom of the bucket--if it does, it'll break off when you set it down. You want to place it high enough so there's some clearance when you set the bucket down or pick it up. I've cracked the bulkhead portion of a cheap plastic spigot by setting a full bucket of wort down and having the spigot take the brunt of the weight--lead to slow leak and some loss of beer, but, thankfully, not the whole batch. When I disassembled the spigot, it became obvious how close I came--the crack was nearly complete, I was able to snap the bulkhead portion in half with my thumb and two fingers.
2.) leave a good inch above the bottom of the bucket (as measured internally) to minimize trub and yeast cake pickup. You can always tilt the bucket towards the end to get the last bottle or two out.