13 years of silence broken!
So I used the millers flush today and then changed the oil and filter. No sign of anything milky in the old oil so all looks good. The two 20 mile runs this week had cleared some of the Mayo at the filler as well. Cleaned out everything I could get to so should all be good now. Just have to drive the long way home more often!
Coincidentally I bought the oil change kit from Opie Oils