Precisely. As your question says, you're trying to mess with axis properties, not those of the figure.
There are routines specific for the ticks or the "dot" notation besides set
OK...did move content to Answer per request. :)
One additional note -- the above retrieves the current axes handle first, then uses it. This ensures always referring to the same axis in the event of some user interaction that could change focus.
Even better is to save the handle when the axes is created (although plot and friends will create one for themselves in which case the above is the way to retrieve it immediately).