I use Fibresafe Gold on 95% of jobs, I just vary the pre spray to suit the carpet and conditions.
However many pH stops above 7 your pre spray is you need to use a rinse which is that number of stops below 7. So if you use a pre spray which is pH 10 (three stops above 7) you will need to use a rinse of pH 4 ( three stops below 7) to bring the carpet back to neutral. You can use litmus paper or a meter to check the final pH of the carpet. Be aware that the carpet may not be neutral to start with if it’s been cleaned previously. Fibresafe Gold is pH 9 but is self neutralising so if you use a neutral pre spray you can clean with a pH 9 detergent knowing it will dry neutral. You can leave wool a little higher than pH7.