Thanks Nigel!
Sounds a good idea but says repeat every 4 weeks??!!
I think I need to get rid of lots of supers & especially brood as they are looking a bit naff tbh??!!
I'll need to order some new 'seconds' frames supers and brood & start again for the most, maybe keep back a dozen or two super frames and half a dozen brood frames!!
Thanks for the info as never heard of a sulphur burner!