I only really do the float test when i have a shrinker,
to see if it's nylon or poly.
I always start with a burns test,did you do a burns test?
The fibre may have had some backing on it to make it float.
I'm a bit bemused why you did a float test,was it to see if it was poly or wool,if so a burns test should of been your first port of call.
Also why did you not do a burn test after you cleaned it and thought it may be wool to clarify.
I'm not being funny,but you should have a good idea by now if a carpet has some wool content just by looking at it.
If you are not sure hold the fibre up to the light,if it reflects light it's more likley to be man made,if still unsure do a burns test.
I always do a burns test on survey anyway to eliminate any suprises.
I'm sorry if i am telling you how to suck eggs and i have not been going that long myself,but some of your questions are dam right
censored.