In the most simple method, the player could kill stuff for five minutes, then run his or her idle alias, then resume killing for 5 minutes, and so forth. If the alias had 11 commands or more, the kill chaser could idle whenever gp regens enough.
A more attractive alternative would be to incorporate the idle commands into the killing process as much as possible. For example, an assassin or thief could initiate combat with backstab once every 5 minutes, peek at the victim, abscond and ambush, and use other targeted commands from the respective 30x command list. Use of the targeted commands would be easiest to track if the kill chaser only takes 1 victim every 5 minutes, and uses all gp during the kill with targeted commands, or afterward with non-targeted commands.
To maximise xp, the player would need triggers to track command use and prompt when a particular command should be used. A (passive) script could record the time when one of your 30x commands is used, and prompt to use it again after 5 minutes. It could also track how many commands have been used after using a command (backstab, for example), then when 10 additional commands have been used, it will add it back to your allowed list of commands to use now. Though complex to implement (especially with accounting for the 11 command cycle), it would probably be worthwhile.
Basically you get kill xp + idle xp + combat TMs. The disadvantage is that you have to be active. It can still be done in groups, though it may take a bit of coordination, so shared group xp and shared TMs are also an incentive. It would allow marginal idlechasers such as priests to get some 30x xp from ritual burying, and the physical guilds could hack and slash without bothering with a training dummy. Witches and wizards could incorporate combat spells for TMs they cannot get with typical idling.
Items needed: a package and a lockpick First I would find a room with an npc and hit my alias, with the name of the NPC to be used as the argument for peeking:
hide unhide conceal package probe package ambush unconceal package hold lockpick lpick slip stick into here peek $*$ palm stick hold stilettoes
If I have enough GP after that, I backstab the NPC. If the NPC survives the backstab, I abscond. But the NPC rarely survives the backstab, so I keep going and killing until I find an NPC that won't die in one hit, so I can enter the abscond command. Then I start over again with the non-combat alias, a backstab, and abscond.
With this technique I earn 380,000 xp per hour (4 gp regen) solo in the AM terrains, versus 250,000 per hour just killing in the terrains, or 200,000 per hour from idling solo.