Nearly full bottle of woodworm spray (Bussage GL6)

See photos. The label says expiry is two years after production but I can’t see a production year anywhere on the bottle or label. We have had this for at least two years so it may not be as effective as a new product. Does anyone want to try it? I think this is roughly the right time of year to treat furniture for suspected woodworm. If you’re interested a mobile number would be very useful to text you our address and how to find us.