Hi
I draw a little diagram for this, but I can’t figure out how to insert it. But I think you will figure it out 
What I want to do is take a guitar signal and split it in an A-B switch. This switch is simply a mechanical footswitch - there is no circuitry.
Path A will go through 3 guitar pedals then into an A-B-Y switch where Y is an output to an amp.
Path B goes directly to the A-B-Y switch for clean tones.
The two ground wires will converge on the ground pin of the Y jack and the two +ve wires will converge on the +ve pin. This means I’ve essentially created a single piece of wire on each side of the Y jack and the signal will be able to pass along both paths. I am thinking that it might not be a particularly good idea to allow this, but I am not entirely sure why, because it’s never going to make a complete loop.
Would it be a good idea to wire a 1N4148 (or something similar) in series with each of the +ve wires in the A-B-Y box please? We are only talking millivolts here. I suppose there is a correspondingly tiny current.
Problem is, the article here talks about current rather than voltage, and anodes and cathodes, which I guess are analogous to positive and negative - but maybe not. Will a diode even work if it is simply being used in series with a piece of wire?
Something else that just came to mind is that the diode has to pass voltage until the guitar signal has completely naturally decayed (or as completely as effectively makes no difference) - otherwise you will have a noise gate, which I absolutely do not want.
Opinions welcome please
Thanks
Phil