Powders/Liquids
Yes i have used liquids before, Its a common fact powders clean better, remove stains better and rinse better, I think liquids are only really good for colour protection as they dont have bleach in, but they are bad for washing machines as continued use of Liquids mixed with Low temperatures can cause mould and gunk build up and bad smells, if you only use liquid on 30 or 40 for example.
As for rinsing im not sure, liquids tend to have more soap in than powders.
If you are worried about rinsing issues, try using white vinegar in final rinse cycle as white vinegar is a mild acid, which breaks down any soapy detergent residue in the wash. Its great for towels and strips away any detergent build up which makes them crunchy and hard.