I use a pair of ascendeurs to go up the mast solo. You can get them from any climbing shop. I use one on a climbing harness and the other in a tape loop knotted at the bottom to provide two short foot loops. This lets me have a foot either side of the mast to lever outwards or upwards. It is important to ensure that the haliards you attach to are attached at the foot of the mast and cranked up tight. It makes moving up and down very easy. I did once watch a friend trying to use a top climber on freely dangling haliard. It's a good way of losing weight.
