I did that on one boat and was disappointed because the knot folds over and is not as comfortable as a solid toggle.

I improvised my own knot which worked fine.

Something like this: to ends of the line coming out from the boat. Once end goes right and back the length of your handle - the other side does the same the opposite way- two lines now lay on one another that have a long pass going one way then back. Then take one end ( either side ) and come back, through the loop on the far end and start winding over all the lines as far as you want for the handle. When you go far enough the line runs under the loop on that end and you tighten it all up and it will lock.

In all honesty, I would have to try it myself again but if I get energetic, I will and maybe post a few drawings. I couldn't find it either and just had to play around until I got one that worked. As I said it will bend in your hand but if your boat is super light, It might be fine. I think a better one could be made with a stick covered with the line.