Dark pool, holy pool, sword pressure, ect.

[Viladin]

So it can't even be used to regain swordskills used based on wording.

[color=#000000][font=Varela, Arial, sans-serif]"While his sword is enhanced with his sword pressure, he can spend 1 point of his sword pressure, as a swift action, to use a swordskill he has already used for the encounter or use a swordskill without expending its use for the encounter. When he spends points from sword pressure during an encounter, he regains a single swordskill use for the encounter."[/font][/color]

Yes, if you somehow have a weapon that's fully maxed out, you can't regain swordskills.