chashmal:
I've owned a lyra lydian beta, helicon and now a Skala. The last two cartrdiges (I had the helicon for 3 years and the skala now for over 2) I have used the lyra fluid about every 3-4 sides of a record. It seems to improve every so slightly the imaging and things slightly are more coherent.
I used the record research fluid nearly every side. And sometimes use the record research (LP#9 I think) to clean and very carefully apply the Lyra fluid. This seems the highest fidelity route.
As long as you apply the Lyra fluid to the brush first, flick away any excess, and only swipe the stylus (you can get a slight amount on the catilever) you'll be fine and you'll get a small incremental improvement in sound...
Also the Cardas frequency sweep record helps. I use track #2 on side one every 25 hours or so.