Although an analog recorder can be, and should be, cleaned by the recording engineer in the normal course of studio activities, a DASH machine should only be cleaned by an expert, or thousands of dollars worth of damage can be caused.
The heads can be cleaned with a special chamois-leather cleaning tool, wiping in a horizontal motion only. Cotton buds, as used for analog records will clog a DASH head with their fibers.
Likewise, an analog record can be aligned by a knowledgable engineer, but alignment of a DASH machine is something that is done every six months or so by a suitably qualified engineer carrying a portable PC and a special test jig in his tool box.
The PC runs special service software which can interrogate just about every aspect of the DASH machine checking head hours, error rates, remote ports, sampler card etc etc. With the aid of its human assistant it can even align the heads and tape tension.
Great home recording starts with a great home recording studio. It doesn't need to be expensive if you know how to select the right equipment for your needs.