Swiss Triplets sound the same as a Flam Accent but they utilize a different sticking.
Flam Accents are lRLR rLRL and Swiss Triplets are lRRL lRRL
Here’s a Video Lesson on How to Play Swiss Triplets
Here’s what Swiss Triplets look like in musical notation
Let’s take a look at the sticking of the Swiss Triplet, shall we. The main rhythm is in a triplet feel and is played with two rights RR and one left L or visa versa. There is a grace note or a flam on the first of the two rights and the pattern repeats so that you will have a left grace note then two right strokes followed by a left stroke followed immediately by a left grace note.
If you just look at the sticking without thinking about the rhythm of the triplet you will have left right right left left right right left left right right left and so on. You should notice that this is really the same sticking as an open stroke roll. RRLLRRLL but its displaced by one of the sticks and then squished together to form a triplet rhythm.
Once you realize this sticking fact you will be able to play Swiss Triplets as fast as you can play an open stroke roll.