I have several containers that are perfect for things i want to grow, and the areas i want to grow them in, but i need to sterilize them (for various reasons, included one was a former cat litter pan).

what would be the best way to sterilize them? they are too large to put in a larger container with bleach :p

you can put the bleach (full strength) directly into the containers and swish it around - or use an old rag to make sure all parts of the container are wet down with the bleach.

rinse with hot water if you can...cold is okay, tho.

for the cat pan, do the bleach treatment and then get some of the enzyme cleaner that removes urine/feces.

make sure the bleach has been rinsed away - i always rinse at least 2 times - because the enzyme stuff will be nullified by any residue that's left from other cleaners/soaps.

follow the package directions. usually you need to shake the container well and then apply the stuff. again with a rag to get the liquid on every surface and then let it sit so the enzymes can do their thing with getting rid of the feces/urine. usually the wait time is about 30 minutes. then rinse with clear water and let dry.

yes, there's still stuff there, even after treating with other cleaners!! and you don't want any of that stuff in the container when you put your plants in it...cats will still be able to smell it, even if you can't!!

also, if you want to use that container for growing foodstuffs, you definitely need to remove ALL traces of urine and/or feces before doing so.

On another thread (I think it was something to do with terrariums) I advised someone to swill out with sodium metabisulfite. This is used in brewing and wine making and you don't have to soak at all just wash out with it with a new sponge. Just one thing. Try not to breath the fumes and if you are asthmatic DEFINITELY do not breath the fumes. Full details are on Wikipedia and I suggest you look at that. THe one beauty of this method is that it is far kinder than chlorine bleaches but far more effective against organic nasties. ALWAYS SWILL WITH CLEAN WATER AFTER USING though.

Plain white vinegar is one of the best cleaners...
*and so is baking soda if you need an extra little gripper for your elbow grease*

Both are au`natural!!!

Another thing is DO NOT use anything else when using bleach...like dish soap they will interact and cause toxic fumes.