No on the dwarf loaches definitely, they need at least 30-inch (75 cm) length tank but having had this species for many years I would not have them in less than a 3-foot length (90cm) tank. Don't let "dwarf" mislead you, these are small for loaches but still a decent size at 2+ inches and they need a group and they are (or can be) active swimmers. Mine are in my 90g 4-foot tank, along with a group of Botia kubotai which are a bit larger (up to 4 inches) and these two are found in the same habitat river and get along remarkably well.
The dwarf golden barb (Pethia gelius) I have not kept, but over on Seriously Fish they recommend 60 cm (24 inches) length by 30 cm (12 inches) width as minimum, which means larger will be kinder to the fish.