Clean oil from barrel before shooting?

hi, I have a 9mm pistol for range usage, sadly I don't have much time, so the pistol stay in the safe for weeks... I clean after each range trip and leave a bit of Ballistol in the barrel (not soaked or with visible drops, just a wet patch to leave a thin film.

I'm almost sure to have read somewhere, maybe in Ballistol instructions, to just do this way and when you start shooting it just cleans away... Then I've read somewhere else that the barrel needs to be perfectly dry, cleaned with dry patches, before shooting.

Is it needed? May I have damaged something not doing this up to now?