Its important to educate yourself on how to properly remove the side plate.
Once you have done that, yes, I remove the side plate on a used or a new gun when I first get it.
No, I don't squirt any cleaner into it ( and never WD 40 - its not a cleaner)...but neither do you necessarily have to remove every part in the gun either ...to make sure there is no mfg residue on a new gun ...or built up residue on a used gun / you can go in with a Q tip and lightly clean up any light residue / but if its got a lot of built up gunk in there, yes, it needs to be taken apart and everything cleaned.
Lube lightly and reassemble...
I have about 15 S&W revolvers...and on revolvers I shoot a lot ( a few thousand rounds a year, I would remove the side plate once a year - inspect, clean and lube). If I only put a few hundred rounds a year thru a gun a year ...I will only remove - inspect, clean & lube once every 5 yrs probably).
I recommend the Jerry Miculek video on doing a trigger job on S&W revolvers..about $20 from Brownells ...and it will tell you how to take gun apart, inspect, lube etc...even if you never want to do your own trigger job its a good addition to your gun hobby library.