you cannot use pat testing machines for fixed wire testing, you have to be a qualified electrician to do this...
for hand dryers you can either do a visual test (look for damage and make sure the dryer switches on and off properly)
or you can disconnect the hand dryer at the isolator and use a safe block to connect it to the machine, then test in the normal way.
again you shouldn't be opening up switches unless you are a qualified spark..