I haven't bothered cleaning the top as I've got a new one waiting for me to pull my finger out and fit it.
But I believe renovo is pretty good, but if you have a red top BE VERY CAREFUL, I've heard that they can discolour and go a murky brownish hue.
If you have a red top, I suggest you seek advice from others with a red top.
"Keep calm, relax, focus on the problem & PULL THE BLOODY TRIGGER"