Data wipe of R930/R230/7920 Rack

I , with a very part time IT responsibility, have been given the unenviable task of erasing data R930 and R230 and Precision 7920 Rack servers before disposing of them. You might say our company should just find a recycling company that guarantees data erasure, but I can't argue the point (  HQ is overseas and not in the mood for any push back on this)

Erasing our 5820 workstations was easy using the BIOS function of "Dell Data Wipe", but I have not been able to find an equivalent procedure for the R930, R230 and 7920 Rack.

I have a USB stick with DBAN I have used in the past , but will the servers even boot off this? I am looking for a more Dell approved method if it exists.

Suggestions?