Willow The Wisp

I've been thinking, would a Parshman in Slaveform be able to, if they had access to feruchemy somehow, store any identity or connection? In the wiki page it says they've been 'robbed' of it or that they 'have none', so can you store something you don't have? What would be the effects if one tried? If they succeeded would they be able to, if they had access to allomancy, compound said identity or connection and thus heal themselves and gain a form? If so, all they'd really need would be the barest sliver of identity or connection, right? Would they need both or would only one do? If a parshman in slave form received a filled hemalurgic duralumin spike would that heal them?