LPT: If you have trouble cleaning out a bottle or jar, wet the area and stick it in the freezer

Sometimes I find myself struggling to get last bits of a condiment, shampoo, toothpaste, etc. out of a bottle or jar. If I add a little water and then stick it in the freezer for 10 minutes or so, the contents will generally come crashing down towards the mouth of the bottle and can easily be scraped out.