I don't know too, i am not btc expert, I am only selling ebooks and digital products and people want to pay btc. Sometimes processing time is a nightmare, so i am using free accelerator from this site https://viabtc.com/tools/txaccelerator/
but it's very hard to take a place ;/ 20 seconds every hour, places taken. I've tested confirmtx but no results, so searching for working stuff.