I like the algea to funk my tank all up. Makes it look more natural in my opinion. Most clumps hanging off my fake plants the better. If you really like a clean look you can run some super hot water over them and scrub. This is going to kill all over the good bacterias that have accumulated on the plant, but wont cause an serious harm. Dont use soap or anything like that. %5 bleach would be ok if you rinse the plants off a couple times afterwards to avoid any risks.