Very similar to what I do. I just use white paper, then fold down the middle & funnel the collected pollen into a film canister, vitamin or prescription bottle, tape around the edge of lid to seal, lable date & strain & pop into freezer. The one thing to keep in mind is moisture kills pollen, so when ready to use, let the container sit out & reach room temp before opening to prevent condensation from getting the pollen. I too have been told you can't refreeze, so I would reseal container & put in fridg & use it up within a month, tossing it out after that. Back in the 70's & 80's, I used to give a few friends pollen, & they said it was still good after 3 months in fridg, but to be sure, I still just toss after one. I found swapping pollen more conductive than trading seeds. Cuts out one whole generation of growing to get a good male!

P.S. just remember to let sit till room temp before opening, even coming out of fridg.

P.S.#2 When I pollinate lower buds, I harvest the top when buds are ripe, leaving the lower to finish the seeds till they're so ripe they fall out with just a gentle touch. Imedietly after harvesting the top cola/ buds, I give a shot of bloom food to fatten up the seeds.