[hankpac]

Oxy tabs are made of iron filings. Finely crushed iron. Like that black powder you get paying with a magnet.
It binds oxygen by oxidizing (rusting), not by pulling a vacuum.
It is important to know what you are using and how it works.
Not knowing leads to mistaken beliefs that perpetuates across the population of people using these materials.
If you want a vacuum, use a vacu-sealer, and seal the mylar after vacuuming, or "burp" the 5 gallon bucket like you used to do with Tupperware.
Finally, you can obtain a large bottle of CO2 from a welding supply, They will drop it off for you (it's a rental, you pay only for the gas used), and put it in your garage.get a hose, regulator and nozzle from the supplier. When filled with product, poke the nozzle down into the bucket, and give a 5-10 second squirt. The bucket is full of CO2 when you can sniff at the top of the bucket, and the CO2 burns your nose (like a fizzy coke when you first start to drink it.) As long as you dip product out of the bucket, the CO2 will stay in it. Don't tip the bucket to obtain product, as the CO2 will pour out too.
I have used this method for 25 years. Works great.