In a word, weird.

In more words:

1) Given the small amount of information you've provided, I'd leap to the conclusion that it's a bad habit.

2) 6 seconds doesn't seem like enough time to accomplish dodges and burns, unless all your prints are straight exposures. I'd suggest closing down a stop to double your exposure time, but that would mean leaving the aperture open 1 stop, and thus disqualify it entirely as it would be an odd number.

3 When a test print is initially made, a less "odd" approach (classic, if you will) may be to use test strips of varying exposure times (at any selected projection aperture) first, rather than trying to force exposures from a single aperture and predetermined time.

4) You may want to take a basic printing course or peruse this. I'm not saying you don't know how to print. I'm just saying your approach seems odd, errr, I mean even, I mean... Oh, forget it.