You should be careful when using cleaners and other chemicals for the tubes. Some cleaners may contain solvents or other chemicals, for example silicone, that can be harmful for the tube material. Wrong kind of cleaner or protector can make a repair glueing very difficult and there can also be other harmful effects.
Use of the hand cleaner sounds good.
The 303 Protectant is designed to give a protection against UV rays for the treated material. It's water soluble so it shouln't harm the tubes, but it may not work too well as a cleaner.
I have used the 303 in my new Zodiac and it seems to be a good product. The tube is easier to clean and the product gives also protection against dirt. Treated surface is a bit slippery when wet and that can be a problem for some RIB and inflatable users.
[This message has been edited by Jari Hjerppe (edited 21 May 2001).]