I found a universal bath plug pretty useless. The only time I really needed a basin or bath full of water was when washing clothes; the action of pulling and pushing the clothes in and out of the water always dislodged the plug.
My pack is under 6 kilos. Here is my complete packing list, which includes the clothes I walk in:
Aarn Featherlight Freedom backpack (small New Zealand company, see
http://aarnpacks.com) - revolutionary design, unbelievably comfortable.
Clothes:
Sunhat.
ASIC running shoes (I don't wear boots), one size bigger than normal.
3 pairs coolmax sports socks (to walk in, washed daily)
1 pair Zero G sandals
Zip off legs quick drying walking trousers (to walk in, washed daily)
1 ultra-fine merino short sleeve T-shirt (to walk in, washed daily)
1 nylon singlet top
1 long sleeve ultra-fine merino cardigan (evenings, cold)
1 sarong (skirt for evenings, cover for bed, modesty wrap from shower)
1 black nylon nightdress; lightweight.
1 nylon rain poncho
Nylon pouch (instead of spongebag) containing:
Microfibre towel, 30cm x 30cm
6 nappy pins (better than pegs)
Childsized tube toothpaste & brush
Neat 3B Action Cream (small tube) prevents prickly heat rash but I use it mainly as a deodorant & anti-perspirant - active ingredient is aluminium chlorohydrate.
Lustre-Cream concentrated shampoo; in a tube. Doubles as body soap and clothes washing detergent.
Antifungal cream. Ibuprofen tablets.
Nivea Visage moisturiser with sunscreen (used daily on all exposed skin, it comes in a small tube)
Nail sissors, airline sewing kit (including needle & thread), earplugs, tiny LED lightweight torch, tiny lightweight plastic hairbrush.
1 silk sleeping sack
1 down-filled sleeping bag liner (instead of a sleeping bag)
In my winter/spring trips I also take thermal long johns & top, a fine silk/pashmina shawl, & ski gloves (all lifesavers). I swap the nylon rain poncho for a lightweight Gore-Tex jacket (hooded) & rain pants.
Kanga