Just a note, the OP asked the difference between the DCC and non-DCC versions of the loco. Clearly that question was answered.
Now it seems to be the best way to clean track, although I submit there is “cleaning” like dirt, twigs, tree sap, etc" and there is “removing oxide” from brass rail when used for track power.
Some of the techniques can do a fair job on both, I use a sweeper car for cleaning/clearing, and a swiffer for removing oxide (really no oxide, removing the black greasy stuff).
The interesting point of “needing the LGB loco vs. using something else” needs to also take into account if the priorities are less personal effort, cost is or not is an issue, etc.
In my brief round with brass, I can say that the cost of the LGB loco was preferable to the manual labor of running around sanding the track.
BUT, everyone has different personal priorities, and sometimes it’s hard not to put YOUR priorities on everyone else.
Greg