this is what I did, I don't have any pics yet.
I took a pressure cooker, bought some door seal at auto parts store that had sticky tape on it and I stuck it to the top edge of the pressure cooker. then I had a piece of 1/4" poly carbonate cut round to fit the top of the pressure cooker. then I bought at harbor freight an air conditioner vacuum pump, https://www.harborfreight.com/air-vacuum-pump-with-r134a-and-r12-connectors-96677.html took out the venturi air pump drilled a hole in the center of the poly, put pipe threads in to attach the air vacuum pump and waaalaaa.
I used it to degass RTV silicone to make molds. when I put the silicone in the vacuum chamber it doubled in volume while pulling out the air bubbles and then when it dropped I took it out an poured it and didn't think it helped much if any. I was told it didn't pull enough vacuum that I needed a regular vacuum pump. I put a gauge on it and I don't remember how much it vacuum but I remember it was not as much as they recommend to vacuum out an a/c line, but I thought it was enough for the silicone but I don't know.
If I remember I will take some pics when I go back to my old shop where my pump it at.