[Speedslug]

I might suggest making sure you don't shake up the contents of your gas canister.

If the tank has crud in it try storing it in the position you use it in .
That should let the gunk settle to the bottom and then moving it gently on to your torch bench.
That may reduce the crap getting to the flame.

But also remember that most of the uses for these canisters is camp cooking, space heating or melting metal so they don't filter the fuel much before filling the tank.