When I said use warm water, I didn't mean to perform the filtration with warm water. I meant to use warm water to break down the pills, then proceed to perform a standard CWE.
Also I've never noticed any difference in codeine output between ibuprofen+codeine/paracetamol+codeine -or even ibuprofen mixtures/no CWE at all - eg, taking 50x12.8mg codeine + ibuprofen tablets and performing a CWE with 100ml, then 100ml re-filter, the two are indistinguishable.
If you really want you can put another 50ml through for a 2nd re-filter, but at that point you're only gaining about 1%-3% from what I can tell.
Also I've never noticed any difference in codeine output between ibuprofen+codeine/paracetamol+codeine -or even ibuprofen mixtures/no CWE at all - eg, taking 50x12.8mg codeine + ibuprofen tablets and performing a CWE with 100ml, then 100ml re-filter, the two are indistinguishable.
If you really want you can put another 50ml through for a 2nd re-filter, but at that point you're only gaining about 1%-3% from what I can tell.