You can be sure their new councillors and MEPs will have been told this. Whether they'll listen, or follow Farage's snout into the trough, is another matter. In fact IMO one thing that might well hamper the party in the coming years is that the quality of its councillors won't be all that good, and there'll be a few resignations and sackings, as well as some disillusionment when the anti-political candidate people voted for turns out to be just another self-interested politician who doesn't turn up to council meetings. Hopefully some of that will start to emerge well before the general election.
I think quite@few of their supporters respect them for 'playing the system'; Paul nuttalls is quite open about the fact he doesn't do his job as an mep properly. In his mind not bothering to attend yet get paid helps the party achieve its goal of bringing down the EU.