Diffuse now with my AquaClear. Even after all waterfall agitation it is still efficient. I don't like the noise of bubbles being smashed, though.
I have also used before a bent and sharpened glass tube on the end of the silicone tube. It had a tiny hole, so it mabe lots of microbubbles per second. This you could combine with any other method, but I don't thinkk with the HOB intake, because the tiny bubbles may get past the impeller without being smashed and dissolved. Haven't really compared the readings, though.
I tried before via Venturi, efficient sometimes, but the last pump would just defeat the pressure and suck up the bottle and yeast solution to 3-4 feet up.
I even once had a lillie growing on the right third of the tankd, and its leaves had covered all surface. Bubbles accumulated beneath them, making for an efficient and aesthetic dissolver.