your problem is most probably the aileron servos and especially their leads.
you can use special chokes placed on the aileron wires near the receiver.
these come in different guises. some are just rings trough which you coil the
servo wires around (if youhave xtra length of aileron servo wires
alternatively electronic supply house have a split suppression filter that you can clamp around the
aeron servo ires again near the receiver.
wrapping the esc without grounding is of little use.