OK! Sorry!
Clap your hands in a steady slow beat, making the first of every three slightly louder- as you would play in 3/4.
For the second two beats, use the fifth and then the fourth finger. These will, as you say, not produce a loud clap, (more of a muted tap!) but this is intended as a drill, not something designed for performance. The virtue of this is that you always know precisely where you are in your bar, or triplet. If you prefer, you can use your palm for the first beat of each three, and the back of your hand for the next two. If you've attended any concerts of classical Indian music you may have seen both performers and clued in members of the audience "keeping the tala" like this.
The point is that you're beating a 3/4 bar with your hands, and speaking words over it. You don't really have to use Ta-Ki-Da, you could use the words "one, two, three" but then all the beats in the two or four would be the word "one" which would be odd, in a way. Perhaps I should have given more thought to my explanation, rather than just slapping it down. My apologies, and I may try to post a clearer version.