Is there anything one can do to save the deceased from the consequences of their Kamma?
I like to make the following points (from a Theravada standpoint.):


Sañcetanika Sutta and Loṇa,phala Sutta deals with how Karma can be eradicated or results can be limited.


If you have done a large amount of +ve Karma then a litter -ve Karma has limited effect
Your Karma ceases to exist when you experience the result. This is something you want to avoid if it is a bad Karma but when doing Vipassana your old stock of fabrication come into the surface and gives you a sensation and passes away if you are equanimous to the experience. These experiences tend to be more milder than Karma giving results in the normal course. See: The Discourse Summaries

Rights and rituals have a place in Buddhism:


This is to keep the institution going and as means to attract people to Buddhism especially who are not yet ready or mature for deep insight
Rights and rituals can be a steppingstone to liberation if the rights and rituals foster morality (sīla,vata), as in (Ekā,dasaka) Cetanā’karaṇīya Sutta
Rites and rituals cannot eradicate Karma at least as per Theravada tradition