blessing a rakshasutra

hey everyone, so I'm an Indian Hindu, and I do practice Hinduism, not by the books, but westernized (NRI). I have a couple rakshasutras from yadagirigutta, and I was wondering if I can keep them at my altar at home, and worship/pray for 3-4 days, so that they get blessed? and if so, can I incorporate some of my desires and wishes, and let the deities bless them, or are they already blessed from the temple itself?