I haven't tried it but at least from this code
https://github.com/AbiWord/enchant/blob/ff5e31d0535ba93f27010a6b1ac50e87252b...
it seems that enchant gets the config files from `~/.config/enchant` (`g_get_user_config_dir()` should return `~/.config` here). So you could try moving the dictionaries there.