Dont use the baking soda its too alkaline. Use the peroxide. Even full strength it will not harm the plant. But 2 parts water to 1 part H202 will do the trick too.
Ed Rosenthal says >
"Hydrogen peroxide is essentially water with an oxygen atom attached to each molecule. Its chemical formula is H2O2. The second oxygen atom is ready to jump from the peroxide to other molecules and to oxidize them. It readily jumps onto mold spores and bacteria and destroys them by burning them up. Peroxide is sold in different strengths. Indoor garden shops sometimes sell 10% peroxide, but drug stores usually sell the 3% strength.
One part of 3% hydrogen peroxide can be combined with two parts water, or one part 10% solution is combined with nine parts water, to make a 1% solution. This solution should be used for cuttings for the first week. Nutrient and amendments can be added to this mix. It can also be used in the sprayer if you mist the plants. It is a sterilizing agent, so your cuttings are much less likely to suffer infection."
Good luck!