You can use chemicals to unclog the drains, but it is the least preferred method for many reasons. One reason is, chemicals like these can damage the garbage disposal if frequently used. Another reason is, chemicals should be used only if the sink is draining slowly. If the sink is completely clogged ie, water is not draining at all, then adding chemicals won't have any effect since they won't reach the clogs. So when you dismantle the pipes at a later stage, you will have to deal with these chemicals.