unfortunately nothing solves stuttering. I also substitute a lot but in some cases there is no substitution. as I said try the soft onset technique, it does help for this type of stutter, for example the word "animal", you want to almost skip the first "a" which causes the block. try to either replace the "a" with a soft/quiet "h" so it will be [h]nimal or jump straight to the "n" like "nimal" it definitely helps but as I mentioned you have to be very relaxed and speaking quietly for this technique to work, and I don't know whether this technique can be used in public efficiently