Rinsing with rice water, blanching in hot water... These common folk remedies for removing pesticides are considered effective by experts, but before doing any of these, the most crucial step is to let the vegetables sit overnight after bringing them home.
Traditionally, people value "fresh fish and fresh vegetables," meaning fish should be live and fresh, and vegetables should be freshly picked, even still damp with dew. However, this old tradition is no longer suitable today. Experts now advise letting the vegetables rest and air out after purchasing them. Leafy vegetables are best left for at least one night, or a minimum of four hours, to allow any residual pesticides to be slowly released. On the other hand, this process also allows the vegetables to undergo a kind of re-ripening, which improves their texture. It's fine if they become a bit wilted; as long as they don't turn yellow or spoil, their nutritional value can actually increase. The same principle applies to fruit. Freshly picked fruit can often have an astringent taste. Letting it sit for a couple of days will result in a better texture and higher nutritional value.