USB input for send / return external effects (SP404)

Hello!

Anyone know if one could use SP404 (or any effects) via USB send / return on mixer?

Meaning - I currently have some pedals into the send / return via 1/4. Works like a dream.

Was hoping to connect another external (ideally my Roland SP404) via USB send return - as switch between the two (using 1/4 switch and usb switch)

Thanks.