As long as you aren't banging anything. I don't see why it would do any harm. You just wouln't want to create a loop. Directly plugging the vacuum's intake into the exhaust.
Given the higher chance of static electricity build up on the vacuum head while vacuuming. I'd keep the computer grounded and yourself grounded to the case via and ESD wrist strap. Even then there is a risk touching circuity boards directly with the brush bristles.
I think the ESD wrist strap is the only real difference with the ESD model. As far as safety for the computer is concerned.