How big is your tank, out of curiosity? If you're overstocked, it will get dirty faster. With my sand substrate, I use an Eheim battery powered vac (doesn't do water changes, just sucks up dirt) to vacuum up loose waste every other day. Once a week, I deep clean 1/3 of the sand. It's important not to deep clean more than 1/3 a week, because you'll destroy your beneficial bacteria and disrupt your nitrogen cycle.
This is actually incorrect. You can deep clean the entire sand bed in a freshwater tank weekly an it will not destroy your BB at all. Your filter and decor also has BB. Look at gravel bottomed tanks. You can clean them once a week as well and not destroy your BB. I have both sand bottomed and gravel bottomed.
The other thing to remember about sand is that it can grow pockets of toxic gases, so at least once a week run a chopstick or clean knife (that has never been touched by soap) all through the sand, back and forth, to get rid of any pockets. Hope that helps.
This is also somewhat false. This would actually depend on the grain size and type of sand being used. Like play sand vs pool filter sand. A very fine powdery sand like play sand will have a higher risk of pockets than a courser sand like pool filter sand. A larger grain size, like pool filter sand, doesn't compact like a smaller grain sized sand like play sand or most of the pet store sands.