Unfortunately the disposable electrodes can only be used once.
We don’t carry reusable electrodes, but I’ve seen them before at doctors offices and they use some sort of suction cup to hold them on the body. Not sure where to get those but you might try asking your doctor or looking around for a medical supply business to see if they can give you any advice.
You can get these reusable EMG electrodes only by an affiliated medical equipments supply company. There are list of companies on the internet just contact them.