Spray it with a 40-50 PPM colloidal silver spray, something like this, no affiliation and not the product I used.
https://amzn.to/2AWi3zL
If you want to reverse 1 branch to pollinate the rest of the plant mark a branch and start spraying it twice a day, 1-2 weeks prior to flipping a photo period plant to 12/12. What I usually do is run a full table and reverse 1 full plant. I separate my plant out while I spray it as I do not want the CS to get onto other plants.
NB: you can not smoke or ingest the branch or plant you sprayed with CS. So you must be careful to contain the spray.