When I clean sand I use a short section of hose and siphon into a bucket, that way you can reclaim your sand and it won't just go down the drain. Hover the hose about 1/2inch or so above the sand and make little circles this will make T hge stuff fly up and you can get it out with minimal sand going as well.
Like others have said it can and will get into your pumps. Especially if you have bigger cichlids, catfish, plecos that kick up a lot of the sand. I have sponges on my intakes and the finer grains get thru still. Mine is Moonlight sand from Carbisea.