8 oz of Betadine is quite a bit. For irrigation you would often use a 1% solution. That's a 10x dilution of the 10% Betadine. So in order to get a half litre of irrigation solution, you only need 2 oz of betadine. I keep a 4 oz bottle and a half litre platypus bag with squirt top in most of my larger kits. That combination would be much lighter and probably smaller than the 8oz bottle alone, and allow you to create up to a litre of solution.