^ i used to use that exact method for PM in flower. Always works and non toxic. h2o2 turns into water in a couple of seconds after it oxidizes the PM. No residuals is the best part.
plants make this themselves during reduction phases, in fact it is a character of peroxisomes and so most organisms.
Additional use of H2O2 should be considered since reduction is already a delicate system easily unbalanced, and safer alternatives exist, including common garden full fat milk. I would drink milk, would you drink H2O2?
In plants, H2O2 is generated in photorespiration - a process that apparently wastefully undoes some of the work of photosynthesis!
Photorespiration occurs through the synthesis of Glycolate from 3PG in the Chloroplast and conversion of Glycolate back to 3PG via the peroxisome. This uses energy in NADH and ATP, consuming O2 and releasing CO2 in the process. One hypothesis is that photorespiration protects plants from photooxidative damage when light levels are high and there is insufficient CO2.
Riboncleotide reductase is responsible for conversion of ribonucleotide diphospates to their corresponding deoxyribonucleotide diphosphates. Ribonucleotide reductase has a tyrosyl free radical which is essential to its action. This radical is produced by an enzyme, NAD(P)H:flavin oxidoreduxtase, which releases superoxide ion, O-2• and this highly reactive radical is converted to H2O2 by the action of Superoxide Dismutase.
Clever new wave nutrient companies are using this knowledge to better equip liquid and powder adds for overall plant health, tweaking of desired traits etc and will include SOD's or SOD promoting capacity, this all means you get a plant that has heightened defensive character and so becomes less susceptible to omnipresent molds etc.
many companies now offer UVC as an alternative, since for my money, not enough is known about the impacts of applying H2O2 beyond that required by the plants natural function, but for my money also, you play with the fine balance of terps and flavs at your own risk, understanding just as MIDI perverts HIFI, we as growers may do the same to our plants by over egging compounds that occur in natural balance.