I know what you mean....but I believe there is not an alternative...(no spray etc..)
Is your unit under warranty?
Few weeks ago I asked for my unit (it has two encoders slowly behaving badly) and they told me to send them...otherwise, if you know how to proceed (or if you know some skilled guy) you can try to replace the encoder by yourself (way cheaper.....e.g. for me shipment from/to Italy is quite money heavy). But they recommend to perform this task by a skilled person, otherwise you can end up damaging the PCB