Is it permissible for my husband to dispose of the proceeds of usurious bank interest by distributing them to the poor and needy, and can I take a portion of this money to help my mother with the expenses of Hajj?

What the husband did by distributing the usurious interest to the poor is correct. What he should have done was to place his money in a current account without interest. This interest should be spent on public welfare, prioritizing those in most need. Therefore, these funds should not be spent on enabling someone to perform Hajj as long as there are those in need of food, drink, and other life necessities. It is not permissible to deposit money in an interest-based bank except in cases of extreme necessity.