I think instead of focusing on recovery, you could use that set to force switches. With priority subpass and a simple resist to fighting-type attacks, it could potentially work on a stall-ish team by forcing switches and giving stat reductions:
Illumise @ Leftovers
252 HP/252 Def/4 SpDef
Bold / Prankster
Charm
Encore / Struggle Bug
Substitute
Baton Pass
Charm a physical sweeper, throw up a Substitute, baton pass out to a counter to the inevitable special attacker that comes in. Think Murkrow but with actually good physical resistances and the ability to bp out of a bad matchup as a tradeoff for lack of reliable recovery. Covers Blissey/Chansey's only type weakness and is fully recovered by Wish. Can also threaten to lock sweepers into stat-up moves that continue boosting to avoid Charm with Encore, such as swords dancers that will continue to boost. Yeah, Illumise isn't going to do much damage no matter what moves it has, but Struggle Bug is also a potential option to soften the switch-in to your special wall and guard against mixed attackers, since the spatk drop is guaranteed and isn't affected by gender (and you can still bp out if you mispredict). Hazards greatly limit this set, but you wouldn't run this shit on anything but a stall team, so ideally you'd keep hazards off so Ilumise can come in to be healed by Wish. Just to show you that this isn't ridiculously fragile once it gets in, here are a few example calcs that assume you stay in and charm the opponent (standard natures):
Vs. CB Haxorus Outrage: (54.79% - 64.67%)
Vs. CB Terrakion Stone Edge: (76.05% - 89.82%)
Vs. LO Sand Force Landorus Stone Edge: (55.09% - 65.27%)
Vs. +1 Guts Conkeldurr Payback: (38.92% - 46.11%)
The calcs aren't really that relevant because you'll just be overwhelmed most of the time by the power of opponents' moves, but a set like this has good viability in lower tiers, where it can actually stay in and take more than two hits without dying, and potentially running Moonlight over Encore to support itself with recovery while softening up threats for the rest of your team to stall. The ability to get something like a Wish+CM Jirachi in on a -2 Hax Outrage with a sub intact can be game-changing, which with the old school physically bulky Wish+CM Spread can actually result in illumise's BP'ed substitute being unbroken by adamant hax's cb outrage. Examples like that are situational and need to be tailored, but the idea is solid by itself.
