I purr by rolling and vibrating the front part of my tongue. It seems to work very well. I have coaxed several big gobblers those extra few yards using that purr. To be honest I never really had a problem learning to purr on a mouth call. I use double and triple frame calls and can purr on them without any problem. IMO a purr sounds the best on a pot call but I don't like to have to move to do it so I use my mouth calls.