[MrFlippant]

Nothing against the device, if you have the spare cash. It looks like it will do what it does.
Most of us just put some scrap sandpaper on the track and give the throttle a squeeze, though.
Note that that device won't "true" your tires any more than sandpaper on the track will. Without something to hold the wheels a set distance from the sanding surface, and bring it closer in sub-mm increments, you're really just making a smoother egg. Better than nothing, but not "true".
If you really want properly trued wheels/tires, then you need a truing machine. There are a few DIY examples on this forum and elsewhere. There is also the Area 3 Tyre True from down under, and the Tire Razor made in the USA, both copies of an earlier design where the entire axle is put into a bracket so that you can do press-fit wheels such as those on Scalextric and most other "toy class" cars. I have a Tire Razor, and it can turn a clunker into a dream.

 

[MrFlippant]

You don't want to. Run the car a few laps, and clean the tires (sticky tape, spin them on a sponge or rag, rub with wet fingers, whatever), and keep running. After a few dozen laps and a few cleanings, the track will be as clean as it's going to get. If the tires just won't stay gripping, try softening them up with a quick rub with WD-40. Or, when you're done, rub in some 3-in-1 oil so that next time you drive, the tires are nice and soft.
There's nothing you can do to keep the tires from picking up dust, but a good tire will maintain grip even with a few specks here and there. But if you haven't run the track in weeks, you're better off using a dust cloth on it first anyway. ;-)