Hi,
For sticky tape residues, benzine is good (far better than Isoprop.).
Lamp oil is not bad either, but it's slower and it stinks (can be cleaned with a strong detergent afterward, but that's double the work) - it's good for soaking prize tags and other sticky tags though and they will nearly fall off after a while, with a minimum of physical work (just make sure the thing it's on is not damaged by the lamp oil).