5d CH, and 236a are both viable, I use them often, but of course not SPAMMED. You HAVE to mixup these options for it to work.
I 5CH all the time against dumb tagers, who think that sledge cures EVERYTHING. Just wait like a second and just chuck out the 5d after, the recovery for sledge is terrible. Sometimes hakumens like to 5c or whatever to try to get a barrier, same thing. You have to use it as a punish though, not just randomly thrown out there. Because if you make it a habit of randomly throwing it out there, your 236c will just blocked. And 236a is really usefull what are you talkling about. Against mashers online yes.. it is useless, but if you can get a player mindtrained hardcore for b and c, 236a -> throw is completely free, or even 236a 4b.