I have both track loco, and.....lgb blocks.
for filthy track, the block. For sap, etc. add lgb fluid or meths to cut through the goo. But…this can result in a film on the track, a mixture of cleaning fluid and sap, etc. which then must be wiped clean with a cloth.
periodically, i use a toothbrush and detergent to remove brass stuff from the pad.
the block is the most effective.
my cleaning loco takes mutiple passes running slowly to come close.
i caution ..some 3m pads are extremely abrasive and will leave tiny dirt collecting scratches.
btw, the LGB cleaning tires, are seemingly identical 3m abrasive used on the lgb block cleaner....whata coinkydink...these seem to last a really long time, like, i have used mine on about 100 ft of track, 3-5 times weekly, 2-3 passes for about 6 months or more a year, since 1993..no need to do the numbers.....the tires are still fine.
thoughts:
1 if track is wet, and or inclined, the cleaning tires may have more traction /purchase than the loco driving wheels....reverse the cleaning wheel leads so they pull. cleaning is almost comparable. tracking through switches is improved. more crud in the cowl.
2 never put weight on the cowl with the cleaning wheels (to increase downward pressure) , youll wear down the gears in short time.
3 clean the dam loco periodically. keep the cleaning wheel axel (at the point of entry into the forward motor block and cowl and other areas clean and remove the brass oxide dust to avoid abrasion, seizing of the axel. (the plastic cleaning tires, can leave tiny tough nylon-like threads from the flanges that wrap the axel). i will remove the cleaning motor block, and go over the area with detergent yearly, relube, etc. i blow the track dust out each time i finish use.