Ge diodes have a lower forward voltage. If one is using that trait to introduce harder clipping via diodes to ground, the price you often pay is a lower ceiling on maximum output level.
One of the nice traits about diodes in general, though, is that their forward voltage is essentially additive. If one 1N34A has a forward voltage of 237mv and another has a forward voltage of 243mv, placing them in series gets you a forward voltage (that voltage level at which they will conduct) of 480mv. What that enables you to do is use them to make incremental changes to forward voltage and clipping threshold, instead of having to think in terms of Ge
or Si or LED, and restricting yourself to big shifts in clipping threshold.
So, yes a back-to-back pair with a GE in series with one of those diodes will get you "asymmetrical clipping", but then so will a 3+2 set of GEs, or a 5+3 set, and so on.
So there is no specific pedal you ought to use your 1N34As for, but feel free to use them to alter the properties of things you have that might presently use 1N914s.