CoralRX is a good one, there’s a few options. Any local fish stores will have some sort of frag dip, it’s recommended to always dip corals prior to adding to your tank or else you’ll end up with pests such as the ones you have on the torch.
Thank you everyone, I tried a freshwater dip for a few minutes and they all fell off! It’s a friends tank so I just noticed them but I let them know to keep an eye out. Hopefully it was the only euphyllia affected