Sellers will sometimes opt to remain in the house after closing via a short-term rental agreement. As the new owner, be sure the purchase contract and rental agreement stipulates that the sellers repair any damage they cause after the closing date.
You can attach a length of soft copper tubing to extend the reach of a blow gun nozzle used with an air compressor. The extra length will allow you to clean out motors and interior machine parts without getting a face full of dust. The end of the tubing can be bent to reach around the back side of motors or into other hard-to-reach areas. Use a wet/dry vac along with the blow gun to help keep dust out of the shop.