Can you control and operate the Lionel Smoke Fluid Loader accessory with DCS remote?
As long as you can configure it under DCS as a TMCC engine, yes, you can.
I have the original TAS smoke fluid loader and that's how I control it from my DCS Remote. If the Lionel "remake"works the same way, you should be able to operate it via DCS, as well.
If so, how do you wire it correctly and control it?
I believe that it would be wired the same way regardless of whether it's controlled by DCS or TMCC/Legacy.