I use a Samson S-Split mic splitter.
I think the mic splitter is the way to go because it has ground lifts on each end. I can't tell you how many times I need to toggle through them at different venues because there is noise.
Unpredictable, too - one time at a specific bar will be fine, the next time there's a ground buzz with theexact same gear. Go figure.
Friends don't let friends clap on 1 and 3.....