I used to do it that way but imo it's really outdated, hobbyists are probably better off going with materials that are easier to both store and use. I also had issues with those heat sealers kind of falling apart over time and needing constant maintenance which was pretty annoying... Here's what I've been using now that's more efficient for me for frags and takes waaaaaaaaaaaay less time to pack up, a lot of retail shops have gone this route as well since people mostly frags these days instead of colonies:
1.
Insulated box liners with
these 6" cube boxes.
2.
Leakproof pee cups
3. Celebrate