After buying one Nalgene Travel Kit (medium), I bought a second (and three individual 30ml round bottles), so I would have a total of four (wide-mouth) round (30ml) bottles for condiments (i.e. salt, pepper, onion powder and garlic granules). Each with their own colour cap (i.e. blue, red, green and white). This left four additional colour caps, which are now on the 60ml square bottles. Three of the four round (*squeezy*) bottles are being used for washing-up liquid, shower gel, and shampoo. The fourth, probably for vinegar or tomato sauce. Nalgene are the the most leak-proof *little* bottles "out there", that I'm aware of. This assumes the squeezy bottles have their regualar (narrow mouth) caps on for transportation. I have the squeezy caps in little "grip-seal" bags for unpacked use, which offer pretty good sealing also.
All this for a backpacking kit, which has to include support for extended use. I began using little Nalgene bottles (for pepper, salt ...etc) in 1987 (while gold-panning in Scotland) and I really liked them. Then used them while gold prospecting in the (upper) Amazon basin. No sprinkler was needed for pepper or salt, just a gentle tap with the cap off. In later years some equipment was lost and I missed those little (*airtight*) Nalgen bottles. Nothing else hit the mark. Now I feel fully "upgraded"! (LOL)
Parcel delivery via "Royal Mail Tracked" (where the parcel is photographed in your hands) was excellent.
