Yes, they are effective. I have had one on every CCW revolver I've ever carried. I have them on every revolver I own with the exception of the ones that still wear the target grips.
Tyler's metal version is the best made IMHO, but the Company itself is run like garbage and they are very frustrating to deal with. They are usually available on eBay. BK grips makes them too but they are plastic. From what I understand BK is much more reliable as a vendor.
Years ago I bought 2 dozen assorted sizes brand new in the original Tyler boxes at a LGS. You might look there as well, but for instant gratification, eBay should suffice.