4-8 drops 2% Iodine per liter of water

Food grade hydrogen peroxide (usually 35% dilution) refers to the fact that it has no stabilizers which cannot be ingested. I can only note that I have a friend taht takes a swig of 3% external use only peroxide (with stabilizers) diluted in water to clear up colds with no ill effect. Peroxide should be in a dark brown container to prevent breakdown. Per travel websites, the Iodine method should work using 4-8 drops per liter of water with a good soak time. Iodine is more effective against critters than chlorine. Boiling would probably denature what is probably your 3% H2O2 (Hydrogen-Peroxid) and I think it would only be effective if potentiated with silver colloid. I'd consider flash steaming vegetables after initial cleaning (opening up crevices to steam) until you can confirm the efficacy and protocol of iodine. God bless!