Rentokil chilli gel wards off problem birds – Home News – UK – The Independent.
Before anyone moans, chilli has two ls in the UK, from whence The Independent comes.
Now I’m no big fan of pigeons, having been adorned by them on more than one occasion. However, daubing their genitalia with chili seems a tad cruel. Tom Lehrer would approve no doubt.
Quieter Elephant 
And everybody hates the pigeons.
I don’t know, it seems a good idea to me. If it does only causes a bit of irritation that is. Something needs to be done about them after all. Personally I advocate the introduction of Peregrine Falcons (:-)), but this might work too.