How to tell my neighbour ?

I really don't think you can say anything. It could cause trouble and ill feeling.

I think Liz is right. you could make a big public display of cleaning your bin with some nice smelly Jeyes Fluid (that's what DH does) or if there is a bi cleaning service in your area make sure they get a leaflet or two. I sympathise I hate smelly bins.

Could you wait until after dark and then spray or sprinkle some bin freshener? They might notice and take the hint, but won't know it was you!

Great idea shysal

It must be hard on the bin men who probably have to empty more than their share of stinky bins. Maybe the Council department dealing with waste disposal could be persuaded to have a campaign against putting organic waste in these bins. Do you have a food waste collection in your area? If not, it might be worthwhile approaching the Council to find out if/when they are going to start this kind of collection.

A mature student where I worked at the SU had a very bad BO problem. He was one of the nicest, most helpful people you could wish to meet. He would drop anything to lend a hand. But the trouble was that nobody actually wanted him to help because you really could not bear being within 20 feet of him. You could walk into an empty room and know for sure that he had been in it at some point that day. It really was that bad.
I bought three bottles of shower gel and left them anonymously for him in a place where I knew he'd see them.
It didn't improve, sadly. I did wonder if there was a bit more to it than just personal hygiene.

I'd bite the bullet and say something (with a smile). It's not as if you are remarking on a personal problem or criticising them.
I know my green wheelie bin which takes garden waste, food etc (even if always wrapped) absolutely honks sometimes. Fortunately it doesn't bother anybody but me. Bins smell, end of.

Teetime had a good idea. Do your neighbours come out to do some gardening? If so you could clean your bin then and make a casual comment along the lines of 'I hate this job, don't you?'.

What is the rest of their hygiene like?
What are they like as neighbours?

Or you could be cleaning your bin when they are outside and ask their opinion on the best bin cleaning product and do they recommend hosing it out or just washing it, waving around your bottle of Jeyes Fluid, Dettox, Flash or whatever.

Once when I went out the back, the neighbour was out there grumbling that his bin was full of maggots and stunk of dirty nappies.

The next time I put some rubbish out I found that my bin was full of maggots and stunk of dirty nappies. Shortly afterwards, the neighbour's bin was full of maggots and stunk of dirty nappies again, and my bin had the house number painted on it.

I line the main dust bin but find it does smell. I use fresh bin ,a Jeyes product and it does help. I am trying to get hold of a local who cleans the wheelie bins around here.what doesn't help, and I know all Gransnet dog owners would be aghast at this, but when our bins are out there are dog walkers who dump their little parcels in any bin as they go past. This includes the recycling bin.

I put all rubbish in black bin bags before dumping it in the wheelie bin. Providing there are no accidental holes in the plastic, the bin never smells.

we still have bin bags in dustbins... much easier to clean.... not that I ever have