Well, I must admit, I don't believe my father ever came up with an "acceptable" 'r'. Acceptable by definition, in our case, meant that "everyone remembered it at the next family gathering". I don't think the 'r' was ever remembered by anyone.
Being that my blog title "Random Ramblings" is an R alliteration, I decided to borrow from it and create my own alliteration "on the fly". I'm quite sure you won't enjoy it nearly as much as I enjoyed coming up with it.
Randomly Ricocheting Rancid Rhinoceros Rectum Rounds