The idea of the calming drugs combined with training, is that your dog can hold it together in the face of major distractions and then you can train him to behave nicely and pay attention to you when the distractions are around, and maybe desensitise him a bit to that.
But if you don't do the training and then you take him off the drugs, he will be like he was before the drugs.
I don't know how well that works in practice (combining drugs and training) personally but it seems to work for some people and some vet behaviourists specialise in it. Seems a waste of the drugs and the opportunity not to try a bit. But you do need a trainer who knows the system to talk you through it and coach your timing and technique.
But keeping him out of trouble will make life more comfortable for everyone too.
Yes I have spoken to a few, problem is that the ones out near me are not very helpful so I am working with keeping things calm and re enforcing the training we have done for years.