I have seen a few chilli tutorials mention it is a good idea to soak chilli seeds in weak tea before planting them. Why do people do this and what does it supposedly achieve?
The aim of it is to mimic the action of a bird's intestines prior to pooing out the seed - many seeds which pass through a bird's digestive system germinate more readily, because the outer coating of the seed has been either thinned or softened as a result, making it easier for the seed to germinate. Chili pepper seeds (depending on variety) are known to be difficult to germinate, some varieties taking up to two months before they do so, and that's largely because of their hard outer coat.
This article here http://www.thechileman.org/guide_starting.php is useful to explain this, under the part headed Improving Germination, but essentially, it doesn't have to be weak tea - some people soak in water, or vinegar, or may scratch the outside of the seed by rubbing with sandpaper or something similar, whatever method they personally favour.