I looked into how to get out of Icchantika status, and it turns out that both the Buddhabhadra and the Dharmakṣema versions of the Nirvāṇa have explanations for how one's status as an Icchantika ends. The status is described as hopeless elsewhere, and people seem to have attached to that idea because it has circulated in some scholarship of limited scope. But if one can gain faith and regret one's former state, then it is no longer hopeless. Faith, in both cases, is given as the main factor involved:
Here the question is not actually about how to end icchantika status, it is about whether a gift will be of great result. The Buddha's denial is in regards to this question—any gift is not just a great gift because one has repented, it depends on the object of giving. The fact that an icchantika ends their status through faith appears to be taken for granted by Cunda in his line of questioning, and the Buddha confirms that while an icchantika has no good seeds left, they can repent and end being called an icchantika. So, the seeds are all about one's past actions—all of them are ruined, but they can give rise to a mind of good—this corresponds to the mind of faith that arises from regret at one's past. I believe this corresponds, in JSS, to our recognising and accepting deeply that we are beings of deep karmic evil incapable of any good whatsoever (only poisoned-good at best). After this regret, one takes refuge—entrusting to the Triple Gem who are all embodied in Amida. The actual answer to Cunda's question is maybe of less import in this matter, but clearly giving to a Buddha is better than giving to other kinds of beings—this obviously is important for Cunda who has the privelege of offering the Buddha his final meal.Buddhabhadra, 897c wrote:Cunda addressed the Buddha, saying, “O Bhagavān! If an icchantika regrets and arouses a mind of faith (信心), repenting their transgressions before the Three Jewels, and if they give, will they not attain a great result?”
The Buddha said to Cunda, “Do not say such a thing. By way of analogy, if someone eats a mango fruit, and obtains therein the kernel and it is ruined after eating, and to verify that the kernel cannot seed, one buries it in the ground and even though one pours water on it, it does not sprout: an icchantika is the same as this. Having ruined his wholesome seeds, if he desires to repent and gives rise thus to a mind of good (善心), there is no possibility that they can then be called an ‘icchantika.’ Giving and observing precepts result in a great result, but results are not equal. Why? Giving to a śrāvaka up to a pratyekabuddha, one attains results that all have that possess the distinctions [of those given to], but only giving to a Tathāgata does one obtain the greatest result. Therefore, it is said, there are various kinds of giving whereby one attains great results.
This one is a bit more straightforward. The essence is the same.Dharmakṣema, 393b wrote:Moreover, a liberated one is called “empty and tranquil,” but this is not indeterminate. In indeterminate one is an icchantika who ultimately is unmoving, they are ones who commit grave crimes and do not complete the Path to Buddhahood. But this is unfounded. Why? If such a person attains a mind of pure faith (浄信) in regard to the Buddha’s True Dharma, then at that time they immediately cease being an icchantika. And if they become an upāsaka then they also attain the end of being an icchantika. One who has committed grave crimes, if they have already ceased committing these crimes, will then be able to become a Buddha. Therefore, if one says one is completely unmoving and is not able to complete the Path to Buddhahood, that is unfounded. In true liberation, all things are without true cessation. Moreover, one who is “empty and tranquil” pervades the Dharmadhātu, thus the nature of the Dharmadhātu is the same as true liberation, and the truly liberated one is the same as the Tathāgata. Moreover, for one who ceases being an icchantika, it is impossible for him to be called an icchantika.