The air moves through a vacuum cleaner much to fast for anything to iginite.
I would classify that statement as "Famous Last Words"... Go get a fridge compressor pump for free, or a water aspirator for $20. Both will generate a better suction than your accident waiting to happen, and will be infinitely safer.
Starting point for reading up on cheap vacuum: Post 429241 (https://www.thevespiary.org/talk/index.php?topic=6122.msg42924100#msg42924100)
(BillyBoy: "Refrigerator vacuum pump links", Chemicals & Equipment)