For quite a few days now, we have had a horrible smell emanating from the bathroom. As we have previously had problems with both the drains in the sink and bath, we tackled those first with washing soda crystals and boiling water. No joy! Then bicarbonate of soda and vinegar - again - no joy!
Nowt for it but to dismantle and clean out the pipes - bit of a smell but nothing too drastic. Put back together and sorted out various tiny leaks for a while - no improvement. Toilet brush was old and smelly so that also went.
One morning, DB thought it was coming from the toilet which I didn't believe as we have bleach blocks in the cystern and descaler is regularly applied under the rim and below the water line. Silly me - he was quite right - very odd though that despite those, it should be smelling.
He checked the cistern first to make sure it wasn't the source of the problem, no, it smelled clean. We both stuck our heads down the loo and the smell was most definately there.
Taking a leaf out of Wendy Gower's 'cleaning the toilet post', he donned rubber gloves, and using neat bleach and an old dish sponge, set to scrubbing as hard as he could under the rim. We live in a very hard water area and he could feel loads of limescale stuck under there. The bleach stayed in place for about 10 minutes, before being flushed away. Quite a bit better.
Then he repeated the scrubbing with limescale remover. Again left for 10 minutes before flushing away. Smell gone.
This morning no smell at all so that was the source. Anyway, after the sponge was thrown away, rubber gloves washed, dried and put into a plastic bag for future use, we decided to repeat maybe every month or two.