brake piston

I'm not biting the bullet and buying Mikes piston caliper tool for maybe a one time use. Surely there has to be other ways to go about this. I've tried soaking them in penetrant, using heat, and tapping them everywhere trying to release these pistons. I don't have air so that's out...

...would you order a new one? I figure some of these holes were gonna let air in eventually, so I ordered a new one.