128GB SSD and 23GB of sleep image + swap file, what to do?

You can disable Hibernate to regain your size in RAM on your SSD/HD: First disable it:

sudo pmset -a hibernatemode 0

Then free up space:

sudo rm /var/vm/sleepimage

... if you want to enable it again:

sudo pmset -a hibernatemode 3

Note: -a means on charger and on battery, -b means battery and -c means with charger.

Alternatively if you have more than one disk you can symlink sleepimage to an HD so it can physically locate there.

Swap

First disable Swap:

sudo launchctl unload -w /System/Library/LaunchDaemons/com.apple.dynamic_pager.plist

Later delete the files:

sudo rm /private/var/vm/swapfile*

... if you want to enable it again do:

sudo launchctl load -wF /System/Library/LaunchDaemons/com.apple.dynamic_pager.plist

A restart will definitively solve the issue.

Even if you kill the offending process, the system won't clear up the swap files - you need a reboot to do that.

Also, deleting the swap files would be a bad idea. You would need to sudo to do it, and if the system has the file open, even if you rm the file, it'll still be kept around as the file handle would be open, so you wouldn't gain the space back.

By all means try it, but it's not recommended :)