Answer
(Fatwa: 1084/209=H/1429)
You must avoid it because (a) It resembles to the act of the astray and strengthens their customs and rituals, (b) Whatever you have heard is not proved form anywhere i.e. it is not proved by any haidth that the petals and flowers leaves placed on graves do dua for the buried person. (J) Spending money on incense is reasonable but to whom do you want to send the incense? If it is meant for yourself or the people present overthere, then it is unreasonable and unlawful. In this case, you should buy incense/attar and apply it on your body and on the clothes of the people as it is commonly applied to others. But if the purpose is to send it to the dead then it is wrong rationally, traditionally, Islamically and customarily. Likewise, it is also irrational how the money gets extra after charity, there would be not extra money had you given it to any poor and needy or spent it in any religious work. Or, you mean something else by ?extra?, if so then you should write it clearly and in full details.
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband