ive seen people do it with no adverse affects but i wouldnt do it.the clay will absorb it and u never know whats going to happend.try using h202 u can aslo use peroxide if u can find a higer percentage of it.just be carefull peroxide is an oxidizer and could potentially cause gassing and a fire,to check this,were gloves and stick your hand in the water every min or 2 and see if its getting warm,if it is ,move that bucket out side a.s.a.p and start flushing the whole container with water to delute the solution....now the chances of u getting something that strong about 70 % are almost impossible,but i dont know were your from and some countrys will sell u this with out proper permits or anything,stay under 50 percent.but 2 be safe u could always find a product made to clean hydroponic systems.