Well, since the algorithm is very slow... your best bet is to use very selectively choosen password candidates (and apply very few rules - or even none - to it).
The best thing would be to try to remember as much as possible from the password:
- which characters were used (only lowercase characters? digits at the end? special charcaters at the end? uppercase characters at the beginning? etc)
- was it a passphrase or a password
- remember the (possibly exact) length of the password
- was it based on words which could be found in a dictionary
etc etc
With all of this information you should be able to hand-craft (yeah, it's almost necessary for such a slow algorithm) a base wordlist and apply some very specific rules (for more details about the attack modes supported by hashcat see: https://hashcat.net/wiki/#attack_modes )
The best thing would be to try to remember as much as possible from the password:
- which characters were used (only lowercase characters? digits at the end? special charcaters at the end? uppercase characters at the beginning? etc)
- was it a passphrase or a password
- remember the (possibly exact) length of the password
- was it based on words which could be found in a dictionary
etc etc
With all of this information you should be able to hand-craft (yeah, it's almost necessary for such a slow algorithm) a base wordlist and apply some very specific rules (for more details about the attack modes supported by hashcat see: https://hashcat.net/wiki/#attack_modes )