Up to a point, a soap will still be soap even if a person adds some type of acid to the recipe such as citrus juice, vinegar, etc. So, yes, it can be done, especially since bar (NaOH) soap is good at hiding the effects of additives like this, unlike liquid (KOH) soap. By adding acid blindly, a soaper is basically playing a guessing game about how much acid she can add and still have useful soap.
When you add citrus juice to soap, you are adding extra water, sugar, and citric acid to the soap. It's hard to say exactly how much citric acid will be added, since various citrus juices vary in their acid content. Lemons are generally the highest in citric acid. I don't have a clue about calamansi.
The bottom line is that if you add 1 gram of pure citric acid to a soap recipe, the acid will neutralize 0.624 g of NaOH and make sodium citrate. If you don't compensate for this by adding the extra lye that the citric acid will consume, then the citric acid will take the lye away from the soap. This will increase the superfat some unknown amount. If you add enough citric acid, the soap won't be very good soap -- there will be so much excess fat, the "soap" will be soft and greasy.
When you add citrus juice to soap, you are adding extra water, sugar, and citric acid to the soap. It's hard to say exactly how much citric acid will be added, since various citrus juices vary in their acid content. Lemons are generally the highest in citric acid. I don't have a clue about calamansi.
The bottom line is that if you add 1 gram of pure citric acid to a soap recipe, the acid will neutralize 0.624 g of NaOH and make sodium citrate. If you don't compensate for this by adding the extra lye that the citric acid will consume, then the citric acid will take the lye away from the soap. This will increase the superfat some unknown amount. If you add enough citric acid, the soap won't be very good soap -- there will be so much excess fat, the "soap" will be soft and greasy.