The theory is sound. You actually want turbulence at the terminus'. But you want laminar flow through the pipe. That's why they don't sell dimpled pipes (or want to dimple the entire slot port). I haven't tested these, but should be good for a few tenths. Probably not worth the added cost in a daily.
And FWIW, the dimples on a golf ball increase the turbulence, but decrease drag due to the size of the wake they create vs. a smooth ball. but... ladies like smooth balls //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif