I stop the motor and platter and use a (clean) cotton tip.
But no matter how carefully done, I always get the feeling the thread is being stressed beyond snap. AND if you've settled your 33/1.3 rpm, 45 will spin too fast. So listening to 45's is always less an urge than a wilfully considered option... also you have to clean your mat after 7"s and 10"s because of fingers placing and removing the records.
It's a good thing the Amadeus sounds so damn good. I still prefer MK 1 looks and options, though.