I was thinking, the weight is likely not heavy with a little loco like that but surely there will be some space to add more?Ideally, the loco will be very heavy with a powerful motor and the cleaning block slung under between the wheels will be sprung to keep a reasonable pressure on the railheads to maximise cleaning.
If the cleaning pad(s) are just lightly skimming the top of the rail, the cleaning effect will be limited.
Also, a track cleaning car would need clean rail already - to have a loco push it around. If this things works in 3 to 4 passes the way they say it does then it is a winner and I have no issues using it. At that price, i already like the paint scheme so if it does not clean track well I only paid 30 more for a paint scheme i like!
I have seen the damage from an LGB cleaner loco that got stuck on the rails! This thing seems like it would just sit there if it got stuck, no damage done. (Not having a scrubbing/mechanical mechanism would be good in this case.) Let's just see if it works! If it does, that price is a good deal and will save time. Maybe i can even run cars behind it while it cleans!?