people have started talking about cells 'effluxing metal', which i do not believe is correct.

Is the problem you're having with (a) a noun being turned into a verb? (a common enough occurence in English and one that seems to disturb some because it doesn't take any sort of derivational morphology, i.e., suffixes, to do like in German or Russian). Or (b) that the newly minted verb is being used in a transitive manner?

As to the latter, let's look at some history: effluxus is the past participle of Latin effluo 'to flow out of, to go forth, to issue from' (effluere). So, we have an English noun, efflux, being derived from what was essentially a Latin verbal adjective. Likewise with effluent, it's from the present participle effluens. Good for us, many Latin verbs have made it into English from Latin past participles: e.g., participate, coordinate, obfuscate. The verb effluo was intransitive in Latin, but it seems to have been used with the ablative in much the same way we used the prepositions 'out', 'of', etc. with flow. Are your colleagues not comfortable with using the verb to flow out of? For example, "The heavy metals are flowing out of these cells"? Discharge might be better: "The cells in question are discharging metals." The thing about to efflux is that it seems to be working for these people. And efflux has a certain meaning for them. Why not go with it? English will survive the innovation. It always has in the past. I'd use the new verb like this, however: "The heavy metals efflux from the cells." Rather than the other way round. I see you're probably trying to attribute some kind of agency to the cells in that they are the ones doing the discharging, and not the metals, but it just sounds better to me.