Pedal damage

Will plugging the instrument input jack into the -phase output of my Rocktron Tsunami chorus (with the +phase output connecting to my amp) in order to create a feedback cause damage to any of my pedals? Doing this created some sick noise but I'm afraid it may have damaged my Big Muff since I noticed more hum than usual when I tried to use it after doing this. My pedalboard goes Boss SD-1 OD->Big Muff Pi-> Ibanez PM7 phase modulator -> Crybaby Wah->Boss BF-2 Flanger-> Rocktron Tsunami Chorus.