The issue, or question is whether an antena tuner can selectively
increase one signal within the mishmash of other stuff you are hearing.
If you receiver is hearing an ambient noise level that is above the
internally noise floor within the receiver then an antenna tuner will
only bring that ambient noise leveI up. If you were hearing Radio Fly
Speck against a background of static and weaker stations, then
adjusting an antenna tuner will increase the signal strength of
everything including RFS. It won't magically lift just that single
station from the mud.

Said another way it isn't possible for a tuner change the difference in
signal strength between the desired signal and all the other signals
that are competing for your ear on the same frequency.

I've tried both MFJ and Grove tuners and the end results were the same.
Tuners can be fun if you want to twiddle some knobs.