Alfalfa sprouts are tiny alfalfa plants, usually grown directly in their container. This should be — though famously has not always been — a sterile hydroponic environment, so there should be no need to wash the sprouts before using them. Store the alfalfa in the refrigerator with the lid on so that it stays moist but not too wet, and do not put it in the "quick chill zone" or leave it out on the counter — if sprouts dry out or freeze, they become unpalatable. If the conditions are right, the sprouts may continue to grow while being refrigerated, so the container can potentially refill itself as the shoots are used. An orange LED in the refrigerator may help them grow.
Alfalfa can be used without any further treatment, or can have its seed casings washed away. A bit of underwater shaking will take off most of the seed casings. Most of these can then be floated away; the rest will remain in the rinse bowl after the sprouts are removed.
Add alfalfa sprouts to a salad, or add them to a sandwich such as a hamburger or taco. Alfalfa sprouts are a good source of vitamin K and chlorophyll and are said to be an extremely healthy food. Because they are more healthy than lettuce, they could be used as an appropriate replacement.
Mixed sprouts have become very common. It is not unusual to see "alfalfa and radish sprouts", "alfalfa and garlic sprouts", or "alfalfa and onion sprouts". This makes for a much more spicy and pungent mix. When alfalfa sprouts are mixed with broccoli sprouts, a mild mixture, although one with a more significant texture, is produced.