Ive been running this for 20+ years and every 6 months as fuels have degraded, it needs the burner decoking.
This is normally an hours struggle with chisels and sharp knives and the like.
Until the courier threw a parcel into the garden containing these:
A 4mm drill bit bored the carbon out of the feed pipe.
And my hands stayed clean. Since a regular Aga service is getting on for £100 these days, it's well worth it.
Just a note for any other Aga owners on here.